Machine gun



` July 21, 1936. c. A. LARSSON fr AL MACHINE GUN Filed Jan. 2, 1934 2 Sheets-Sheet l www July 21, 1936.

C. A. LARSSON El' AL.

MACHINE GUN Filed Jan. 2, 1934 2 Sheets-Sheet 2 Patented July 2l, 1936 UNITED vSTATES PATET MACHINE GUN British company Application January 2, 1934, Serial No. '704,835

In Great Britain February" 6, 1933 Z Claims.

This invention relates to machine guns of the barrel recoiling type in which the lock is connected by a connecting rod to a spring controlled crank pivoted to recoil plates connected to the barrel.

The main object of the invention is to accelerate return of the recoiling parts to the firing position.

In order that the said invention may be clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawings in Which:--

Figure l is a side elevation of the rear portion of a gun provided with our improvements,

Figure 2 is a central vertical longitudinal section' of Figure 1,

Figure 3 is a section taken approximately on the line 3, 3 of Figure 2 but with the recoil spring and its associated parts removed,

Figure 4 is a sectional plan of Figure 1.

Figure 5 is a sectional view showing the forward part of the gun, the rear part of which is shown in Figures 1 and 2, and- Figure 6 is a View similar to Figure 2 but showing the parts in the maximum recoil position.

A (Figures 1 and 4) is the connecting rod which is pivoted at its front end to the lock A4 and at its rear end is pivoted at A to the spring controlled crank B having a spindle B' pivoted in the recoil plates C, C connected to the barrel, all as is well understood, and D is the recoil spring for opposing the rearward movement of the recoiling parts and for returning them to the forward or firing position.

The crank is provided with a downwardly extended projection B2 which co-operates with a roller E as the crank moves rearwardly on recoil so as to initiate the angular movement of the crank. The said projection B2 is for practical purposes composed of two limbs arranged one on each side of, and at equal distances from, a vertical longitudinal plane containing the axis of the gun as shown in Figure 3 but it is theoretically a single projection and is herein regarded as such. The recoil spring D is in the form of a helical compression spring the front end of which bears against a bracket D pivoted at D2 to the crank B, the pivot D2 and the bracket D' being situated above the level of the axis of the crank as shown in Figure 2. The rear end of the spring D bears against a washer D3 that is provided with a rear curved surface resting in a correspondingly shaped recess in the front end of a screw-threaded plug D4 carried by the handle block D5, rotation of this plug varying the initial compression of the spring. The said bracket D' has a rod DX projecting through the spring D to centralize the latter, the rear end of this rod passing through a hole in the washer D3 and being provided with a nut dx. 5

The crank B also has cam faces B3, B3 above the level of the axis of the crank in the forward position for engaging stationary surfaces B4, B4 to limit the angular movement of the crank during recoil. Furthermore the recoil movement of 10 the barrel is cushioned by means of spring plungers B5, B5 which are carried at the rear ends of the side plates of the gun casing and with which the rear faces of the aforesaid recoil plates C, C co-operate during the recoil movement of the 15 barrel.

The spindle B' of the crank B may project through both side plates of the gun casing as shown in Figure 4 to enable the crank handle BX to be connected to either of the projecting por- 20 tions of the spindle.

In Figure 5, R is the gun barrel and A4 is the gun lock to which the rod A is pivotally attached at A3.

Upon recoil of the barrel and recoil plates, 25 the pivot B1 is carried rearwardly and the projection B2 engage the fixed roller E whereupon the crank will rotate about the pivot B1 and the spring D will be compressed. As the crank rotates, the pivot D2 moves around the pivot B1 until the two 30 pivots are nearly in alignment with the spring and further recoil is then stopped by engagement of the surfaces B3 with the stationary surfaces B4. At maximum recoil therefore the spring will exert only a small turning moment on the crank 35 and will thus act with increased pressure on the barrel to accelerate the return of the barrel to its forward position. Following maximum recoil the surfaces B3 will rebound from the surfaces B4 to assist return of the crank. A dead centre ar- 40 rangement at the forward position is avoided by the part D1 and pivot D2 being above the pivot B1.

What we claim and desire to secure by Letters Patent of the United States is:-

1. A machine gun having a recoiling barrel, a 45 lrst pivot connected with the barrel so as to move with the latter in the recoiling movements of the same, a crank located on and movable around said rst pivot, a recoiling lock pivotally connected to the crank, a second pivot mounted 50 upon said crank and located with its axis above that of said rst pivot,a member mounted loosely on said second pivot and extending rearwardly therefrom, a helical recoil spring for opposing the movement of the recoiling barrel and crank 55 and for returning them to the forward position, said spring having its forward end seated upon said member and such forward end being located above the axis of said first pivot, an element pivotally mounted with respect to the gun casing and formed to receive the rear end of said recoil spring, and means acting to` limit recoil movement of the crank When the latter has reached a position in which the recoil spring is at maximum 10 compression and when said second pivot has swung around with the crank until its axis is almost inY line with the axis of said first pivot with reference to the line of action of said spring.

2. A machine gun as claimed in claim 1, having faces on the crank above'the level of said pivot in the forward position, and stationary members for engagement by the said faces at maximum recoil to limit recoil shortly before the rst and second pivot would have reached a position of alignment with reference to the recoil spring.

CARL ALFRED LARSSON. PERCY REUBEN HIGSON. 

